galaxy tab 10.1 p7500 shut off- bricked?

hey to all, its my first msg here so ill try to describe as much as i can
I'm reading in XDA for a while, almost every question i had i found the answer here somewhere so thanks all all of you!
i have the p7500 tab with JellyBeanRom ICS v6 XXLQ8 with the A1 kernel (installed it few days ago, till then i was with JellyBeanRom ICS v5.1 i think)
Two days ago i found my tab off, i tried to turn it on and no respond, only after at least 10-15 tries of holding the power and vol+ or vol- and just holding each one of them separately for 20-60 seconds one the combinations boot it on.
I used the tab like nothing happened , fixed permissions and it worked fine until the screen went off (i think only when it was in 'deep sleep' cos i turned off the screen few times only for few sec and it was ok). sine that moment the tab was off again for 12 hours, only today again after lots of tries and strange combinations i succeed to boot it again.
I installed the rom again, wiped every option, fixed permissions again and used again the tab for 45 min (while he was with screen on) and it worked ok, connected it to the pc and it was fine, i went to a meeting with the tab in my bag and i got out and the tab is still off.
when its off, the computer doesn't recognize it, the tab is no charging since the morning and still nothing.
any idea please? i have a cwm backup that maybe can help me but need to boot first

i didnt thought to look it up at the first time cos i thought its only a glitch cos i turned it on again and it worked fine, the 2nd time i reinstalled the rom and wiped everything..

-Have you tried charging with charger and not the PC? Yes, tried few chargers and 2 different cables
-When you plug it in to the wall, do you get the battery icon, even for a short few seconds? nope, didnt got anything, no battery icon.


Just to confirm, you have tried holding the power button for 30-40 seconds and it doesn't do anything? Do you feel it vibrate at all? yes i tried it, i even used a tape to hole the power button for few hours, and also to hold power and vol-.. and no vibration at all



if ill take it to samsung lab, they have any way to know that i changed rom? cos if its off, i can tell them that i didn't changed a thing and like this the warranty still good

please help..?